55 E12 Pickup HD Differential Question - Choices?

[HammondA100]

I've been talking to the lad who has the 55 truck you may have seen on Ebay with the 259. He says the max speed is 50 at 400 RPM approx so must have a monster load capacity of a differential. The truck does have the 3-Speed w/ Overdrive.
I know nothing about the dimentions of this unit but I do have a spare Dana 44 from a 55 President. Dont know if it will fit with the rims the other way or not. He says this diff is the first he's ever seen with the cover on the side. Anyone know what this is or have a link to a photo? Another friend said there is a typical Dodge rear end you could fit nicely under there. Another said there was a "gear vender" type diff available which could shift. the present owner doesnt know what's i there and hopefully will snap a picture tomorrow. Well just looking for alternatives as it's a nice truck to keep up, modify brakes and other saftey features and can handle the loads I deal with (55 gal drums, etc).
Thanks!

[PackardV8]

The '55 E12 came with the great old Timken vertically split rear axle. Yes, it is hell-for-stout. The very rare early '56 E12s had Dana 60 which will directly interchange and use the same wheels. Nothing else fits and uses the same wheels. Maybe it's just me, but I think those old Budd wheels are what makes the look of the early 3/4t trucks.

Who knows what gear is actually under his truck. I can't imagine an overdrive-equipped E12 topping out at 50 MPH. I drove a 4-speed transmission -no overdrive - at 60 MPH for twenty-five years. Yes is was noisy. No, it didn't hurt the engine a bit.

thnx, jack vines

[HammondA100]

Thanks for the quick answer. Well not a lot of luck searching for truck differential which could replace it to match the budd wheels. If a DANA 60 works there must be a million different combinations looking on ebay (semi-floating and bolt pattern). But one way to overcome this is with a gear vendors splitter? I wonder if this Truck Dana 44 would work just by using the right axle shafts. I searched Dana 60 in the forum and nothing comes up but the Dana 44's all over so anyone who has a E12 please let me know what axle you have as this Timkin split unit won't work for my purposes.

[HammondA100]

Here's a reply from the seller:

Here's a picture of rear axle and rear tire.thre's a tag with these # model 51524nx14 serial#4857 there might be some other #'s to the serial that I can't make out but the model # is correct.There is approx 43" from spring to spring.

So that said, anyone got a good differential 43" from spring to spring?

[PackardV8]

Yes, The spring-to-spring measurement is the least of the problems. The '55 is a relatively narrow tread width. Most Dana 60s will be too wide. Then, you'll have the ugly 8-lug wheels on the back and the pretty 6-lug Budd wheels on the front.
Yes, a Gear Vendor or US Gear overdrive unit will reduce RPMs 20-25% at a cost of $2500.

No, the Dana 44 is a passenger car axle and not suitable for 3/4t use. All the '56-64 3/4t Stude trucks used Dana 60s, but in a wider treadwidth than the '55 Timken. Again, the early '56 is the only one with the Budd bolt pattern.

Maybe, Something isn't computing here.All the 3-speed overdrive E12s I've driven cruise easily at 65 at way less than 4000 RPMs. Suggest you'd better get the truck and confirm which axle ratio it actually has. Then, confirm the speedometer reads correctly - 99% of Studes are way off. Then, confirm the overdrive is working.

[jclary]

I've been talking to the lad who has the 55 truck you may have seen on Ebay with the 259. He says the max speed is 50 at 400 RPM approx so must have a monster load capacity of a differential. The truck does have the 3-Speed w/ Overdrive.
Thanks!

Wow! I would love to be able to run 50 at only 400 rpm! However, I am assuming that you left off a zero. Sounds to me like the overdrive just is not working. I have an old E12 with the same rear end but have not had a chance to see how it works. I am still in the "take apart" mode. When and if I get around to getting it back together, I plan to use it and couple it to an overdrive. If you get it going, let me know how it performs.

[HammondA100]

My best guess is the rear end is 5.57 ratio!! Im having him check the overdrive but I will only buy if I can solve this problem. A 4:11 ring and pinion was available for the identical F2 Fords but finding one is a stunt. I did find a Dodge A-Body Dana 60 with a 5 bolt pattern but can't verify it would fit the Budd wheels. It does have the 43" spring pearch though although I would have to weld in the proper mount for the shock which I can do that. I'd much rather find these 4:11 gear sets but not likely.
4.86 was an option for Studebaker.

I assume the 55 used the shorter wheelbase to allow for a dual wheel option? The fenders allow for plenty of expansion.

[PackardV8]

The 5.57 ratio is very uncommon with an E12 V8 truck. I've never seen or heard of one. If there is a 5-bolt Dana 60, it would have come from a 1t or larger and is also uncommon. The E12 is a 6-bolt wheel.

When you're saying shorter wheelbase, are we to take it to mean you mean track width? If so, no. The track width was correct for the 4' wide bed used '49-55. When the bed was widened in '56, so was the track width. AFAIK, Stude never offered an E12 dual wheel pickup box. The dual rear wheel trucks were one-ton and larger with flat beds or dumps.

Bottom line, finding a bolt-in rear axle is not going to happen. However, making up a custom Dana 60 with TwinTraction is pretty common order for the Jeep and 4X4 shops. They build them every day. They could put your E12 hubs on one and thus you could keep your stock wheels.

thnx, jack vines

[HammondA100]

Thanks Jack,
Well I got the good news. Found a vendor who makes a 4.11 kit for that diff. Although the cost is $800 it is all new machined parts and bearings. Problem solved!!